Machine for hardening plates



C. G. OLSON. MACHINE FOR HARDENING PLATES. APPLICATION FILED NOV. 25, 1918.

Patented Apr. 20,

UNITED STATES PATENT @FFICJ.

CARL G. OLSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO ILLINOIS TOOL WORKS, OF

CHICAGO, ILLINOIS, A CO MACHINE FOR 1,333,465, Specification of RPOR-AIION OF ILLINOIS.

RDENING PLATES.

Application filed November 25, 1918. Serial No. 263,986.

To all whom it may concern Be it known that I, CARL G. OLsoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Machines for Hardening Plates, of which the following is a specification.

My invention is embodied in a machine for hardening or tempering comparatively thin metallic sheets for example, of high speed steel for use in circular saws and other articles. I have constructed a press having metal plates adapted to engage the opposite sides of the work for chilling it and consequently hardening it. The general object of the invention is to prevent the work from becoming chilled on one side, and hence distorted before the press closes. Another object is to provide a simple and efficient machine for quickly conveying away the heat from the opposite sides equally, thus hardening the work uniformly and preventing warping and buckling.

These objects are accomplished by the mechanism illustrated in the accompanying drawings in which- Figure 1 is a front elevation partly in central section of the entire press.

Fig. 2 is a top plan view of the lower plate and parts associated therewith.

Fig. 3 is a detail of one of the supporting pins, the parts being shown in section on the line 33, Fig. 2.

Like reference numerals denote like parts throughout the different views.

In the form of machine selected to illustrate the invention the cylinder 1 is supported upon a base 2 and has a plunger 3 working within it. The plunger is moved by an actuating fluid, preferably compressed air, led into the bottom of the cylinder through duct 4. A valve 5, having a handle 6, is provided which is so constructed that when moved to one position it admits the motive fluid to the bottom of the cylinder and when turned to another position the motive fluid is permitted to escape.

Mounted upon the upper projecting end of the plunger is a chilling plate 8 which has behind it a chamber 9 adapted to contain water or other fluid for keeping the plate cool. The upper chilling plate 10 is similarly provided with a chamber 11 supported by a stem 12 from the crosshead 13.

The crosshead is supported upon rods 1% rising from the bosses 15 formed at the upper end of the cylinder. It is desirable that the chilling plates 8 and 10 be made of copper or other metal which will readily conduct heat. A duct 18 leads to one end of chamber 11 while a flexible duct 19 leads from chamber 11 to chamber 9. A duct 20 leads away from chamber 9, thus allowing water to flow through the two chambers for keeping the plates 8 and 10 cool.

Pins 22 extend up through the'nether plate 8 for supporting the work 23,'which is here shown in the form of a circular saw. The

upper ends of the pins are pointed for the purpose of insulating the work to a great extent and preventing it from becoming prematurely cooled on the underside. These pins are backed up by helical compression springs 25 shown in Fig. 3. The lower end of each spring rests upon the floor of the chamber 9 and the upper end engages a collar 26 formed on the pin. The collar also serves to limit the distance to which the pin may project above the top of the chilling plate. The pins are inclosed in housings 27 to keep them out of contact with the cooling water which flows through the chamber. ,Vhile the particular design is non essential, Fig. 2 shows these housings arranged radially, and extending from the periphery toward the center of the chamber. The housings are uniformly spaced, angularly, and the pins are uniformly spaced in the housings with the result that the work is supported from many points, uniformly distributed over the surface and hence pre venting the hot piece of work from sagging at any point.

In operation, the parts are first brought to the position shown in Fig. 1 in which the plunger is lowered and the pins are in upstanding position. The work 23 is then laid upon the points of the pins 22. whereupon the attendant manipulates the handle (3 in such manner as to admit the air or other motive fluid to the bottom of the cylinder. This causes the plunger to rise and move the work toward the upper chilling plate 10. The movement of the plunger is rapid and only a short interval elapses between the time the work comes in contact with the upper plate 10 and ti e time the press closes. The pins 22 yield after the work has reached the upper plate, and permit the press to close upon the work. But the work does not come into contact with the nether chilling plate until the press closes, and hence the chilling action takes place at the top and bottom practically simultaneously. Comparatively little heat will be drawn away from the work prior to the closure of the press and hence the chilling and hardening will take place without buckling the work. The cooling liquid flowing through chambers 9 and 11 keeps the chilling plates cool and the pressure of the machine upon the work and the fact that the cooling takes place practically simultaneously at the to; and bottom of the work results in the production of a perfectly flat article. After the chilling has been accomplished, the attendant manipulates the valve in such manner as to release the motive fluid from the cylinder and permit the plunger to descend. As it descends the pins 22 rise, lifting the work off the lower plate and making it easy to remove the work from the press.

As a result of the foregoing it is not only possible to turn out work rapidly, but the article is chilled uniformly and the generation of unequal internal strains consequently avoided. Consequently, the article is not only fiat when it comes out of the press, but tends to remain flat, and as there are no internal strains, the article is stronger than it would otherwise be.

It will be understood that while the chill ing plates are here shown to be perfectly flat, which they must be for most classes of work, there is no inherent reason why they may not be slightly curved if the work in hand calls for such configuration.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is 2-- 1. A chilling machine having horizontally arranged chilling plates relatively movable toward and from each other, and support ing means for supporting the work above the nether plate, said supporting means being downwardly yieldable.

2. Organized mechanism having a chil ing plate, pins yieldable toward said plate for temporarily supporting the work and holding it out of contact with said plate, and a second chilling plate adapted to descend on the work and force it toward the first mentioned plate and thereby cause said pins to yield.

3. A press having two chilling plates arranged horizontally, one being vertically movable toward and from the other, the nether plate having a plurality of pins for temporarily supporting the work, said pins being downwardly yieldable.

4-. A press having two chilling plates ar ranged horizontally, one being vertically movable toward and from the other, the nether plate having a plurality of pins for temporarily supporting the work, said pins being downwardly yieldable and sharpened to make but negligible super cial contact with the work to avoid premature chilling thereof.

5. A machine for hardening thin plates consisting of chilling plates movable relatively to each other and adapted to engage the work between them, means for yieldingly holding the work out of contact with a chilling plate while the chilling plates are moving toward each other, and means whereby cooling fluid is maintained at the back of a chilling plate for keeping it cool.

6. A steel-hardening press having a frame, chilling plates for engaging the work between them, a cylinder to which one of the plates is rigidly connected, a plunger working in said cylinder and connected to the other plate for operating it, and means associated with one of the plates for yieldingly holding the work out of Contact with it while the press is closing.

7. A steel-hardening press having a frame, chilling plates for engaging the work between them, a cylinder to which one of the plates is rigidly connected, a plunger work ing in said cylinder and connected to the other plates for operating it, and pins associated with one of said plates for yieldingly holding the work out of contact with it while the press is closing, said pins having points for contacting the work and being backed up by springs to make them yieldable.

In witness whereof I have hereunto subscribed my name.

CARL G. OLSON. 

